Half to james richmond knowlson



W. 0. KNOWLSON.

VALVE GEAR FOR ENGINES.

(No Model.)

lllll l ("ll-Ill Patented June 17,1890.

WITNESSES.- MQ%w;

ATTORNEY.

mum, WwHINGYQN o c UNITED STATES ATENT OFFICE.

\VALTER OSGOOD KNOlVLSON, OF TROY, NEIV YORK, ASSIGNOR OF ONE- IIAIAF TO JAMES RICHMOND KNOIVLSON, OF SAME PLACE.

VALVE-G EAR FOR ENGIN ES.

SPECIFICATION forming part of Letters Patent No. 430,528, dated June 17, 1890.

Application filed March 24, 1890. Serial No. 3%,099. (N0 model.)

To all whom it may concern.-

Be it known that I,WAL'rEROsoooD KNOWL- SON, a citizen of the United States, and a resident of Troy,in the county of Rensselaer and State of New York, have invented certain new and useful Improvements in LiberatingValve- Gears for Steam-Engines, of which the following is a specification.

My invention relates to improvements in liberating or releasing gears for steam-ind uction valves for steam-engines; and the objects of my improvements are, first, to make a liberating-gear that will offer the least possible resistance in its action to the operation of the governor; second a tripping-lever hung or fulcru med upon the lever which is secured to and moves the induction-valve, and, third, a reverse catch-bar attached to the trippinglever to give a positive return movement to the valve-lever should the dash-pot fail to operate. I attain these objects by the mechanism illustrated in the accon'ipanying drawings, in which I Figure 1 represents an end view of the gear in position. Fig. 2 represents a side view of Fig. Fig. 3 represents a section through a a, Fig. 2. Fig. at represents a top view or plan of Fig. 2.

Similar letters refer to similar parts in the several views.

A is the valve-lever, keyed upon the valvestem B.

C is the tripping-lever, carried upon f ulcru mpin D on valve-lever A.

E is tripping-lever pin on trip-lever C.

G is valveconnecting rod connecting tripping-lever pin E to wrist-plate pin E.

II is latch-lever hung on stud-pin L on valvelever A.

I is a roller carried in joint of latch-lever upon stop-pin M.

N is a spring pressing stop-pin M against valve-lever A.

O is valve-stem bearing. (Shown broken.)

Q, Q is dash-pot lever and pin for connccting to dash-pot.

In operating this releasing-gear, when the parts are in the position as shown in Fig. 2, with the latch securing the tripping-lever, the movement of the wrist-plate by means of the connections causes the valve to be opened, and according to the position the governorlever cam J is set in it will determine in relation to the speed of the governor the point at which the latch-lever will be released. It will be noticed that the inner corner of the latch on latch-lever where it engages the toe of the tripping-lever is in a direct line with the center of the pin L, upon which the latch lever is hung, so that the holding part of the latch is confined to a line central with the pin when the movement of the wrist-plate is transmitted to the tripping-lever, which is held by the latch-lever. The slightest contact of the roller on the latch-lever with the governor-lever cam disturbs this narrow line of pressure, and the further movement of the tripping-lever causes the latch-jaw to move upward and away from the toe of the tripping lever, thus taking the strain off the roller of governor-cam and allowing the governor to act freely. The further movement of the toe of the tripping-lever causes it to travelin a curve the reverse of the curve on which its fulcrum on the valve-lcver travels. Thus all drag or friction which is common to trippinglevers which work around the center of the valve-stein is avoided and the evils incidental to that system of liberating-gear got rid of.

Upon the tripping-lever G a reverse catch bar P is formed. Its function is to carry back the valve-lever so as to cover the ports in case the dash-pot or its attachments should fail to operate.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In a liberating steam valve-gear, the combination of a tripping-lever with a releasin g latch-lever, both carried by and operating with the valve-lever, substantially as specitied.

2. In a liberating steam valve-gear, the combination of the valve-lever with the reversing catch-bar on tripping-lever, substantially as specified.

3. In a liberating steam valve-gear, the combination of a tripping-lever with reverse catch-bar and releasing latch-lever, all attached to and moving with valve-lever, substantially as specified.

Signed at Troy, in the county of Rensselaer lo and State of New York, this 21st (lay of March, A. D. 1890.

FRANK O. CURTIS, V. H. HoLLIsTER, Jr. 

